2.5. RT-qPCR assay

The total RNA was individually extracted from spinal cord tissues and BV2 cells. Ultraviolet spectrophotometry detected the RNA integrity. cDNA was synthesized by reverse transcription of PrimeScript RT Reagent Kit (Takara, Japan). According to the instructions of SYBR Premix Ex Taq kit (Takara, Japan), the PCR reaction was performed, and the conditions were 95 °C 5 min, 95 °C for 20 s, 60 °C for 30 s and 72 °C for 20 s. A total of 40 cycles were performed. 2^−ΔΔCt method was used to calculate the relative expression level of the genes.